I trying to mount an ext4 sdcard on a Samsung Galaxy Tab a6 (sm-t580) running Android 6.0.1. It has the original ROM, but is rooted and has TWRP installed.
I've tried the following commands on adb:
mkdir /mnt/media_rw/0000-FFFF mount -t ext4 /dev/block/mmcblk1p1 /mnt/media_rw/0000-FFFF
This sucessfully mounts the volume and the volume can be viewed on the command line but is invisible to the gui. I follow with this command.
/system/bin/sdcard -u 1023 -g 1023 -U -1 /mnt/media_rw/0000-FFFF 0000-FFFF
But this spawns the following error:
E sdcard : cannot mount sdcardfs filesystem in default (error 2)
When I run the last the sdcard command as an ordinary user I get
E sdcard : Error setting RLIMIT_NOFILE, errno = 1 E sdcard : installd fs upgrade not yet complete. Waiting...
The second line of which repeats indefinitely.
I also tried running
vold but that just prints out
Aborted on the standard output. Running the following command triggers a mount
/system/bin/vold --blkid_context=u:r:blkid:s0 --blkid_untrusted_context=u:r:blkid_untrusted:s0 --fsck_context=u:r:fsck:s0 --fsck_untrusted_context=u:r:fsck_untrusted:s0
but just results in the following on logcat
no match partition type(131) -> change table to kUnknown disk:179,32 has unknown partition table; trying entire device ... Failed to pclose /system/bin/blkid -c /dev/null -s TYPE -s UUID -s LABEL /dev/block/vold/disk:179,32 : File exists [WARNING] blkid failed to identify /dev/block/vold/disk:179,32 disk:179,32 failed to identify, giving up
Which is the same as when you insert the sdcard in to the device.